Yarn brakes of the above described type are utilized particularly in conjunction with two-for-one twister textile yarn processing machines, as disclosed in German Pat. No. 968,222 and U.S. Pat. No. 2,718,363. However, such yarn brakes may also be utilized in other environments, such as for example with any hollow spindle, bobbin adapter and the like, wherein yarn is fed through a tube and tension is to be applied thereto.
In two-for-one twister textile yarn processing machines, the yarn brake of the above-described type may act either as the sole tensioning device for the yarn passing through the hollow spindle or, as is more frequently the case, may act as an initial tensioning mechanism which precedes a further yarn brake tensioning mechanism of the type utilizing capsules or platelets for tensioning of the yarn within the hollow spindle of the machine, as is well known to those with ordinary skill in the art.
Moreover, in modern day textile yarn processing machines, particularly two-for-one twisters, threading of the yarn through the hollow spindle assembly is often performed pneumatically by mechanisms, such as disclosed in commonly-assigned U.S. Pat. Nos. 3,945,184 or 3,975,893. With the use of such pneumatic threading mechanisms, the brake member of the yarn brake must be moved away from the upper end of the tube or some other provision for threading provided.